「不知天高地厚 / 不知地厚天高」

(pos:語句)
<explanation>
yue:狂妄自大，唔知自己有幾多斤両
eng:to have an exaggerated view of one's own abilities; literally: not to know the immensity of heaven and earth
<eg>
yue:居然挑戰世界冠軍，真係不知天高地厚。 (geoi1 jin2 tiu1 zin3 sai3 gaai3 gun3 gwan1, zan1 hai6 bat1 zi1 tin1 gou1 dei6 hau5)
eng:He audaciously challenges the world champion with overconfidence in his abilities.